Typical labyrinth type rotary shaft seals are shown in Rockwood, et al., U.S. Pat. No. 4,572,517 and U.S. Pat. Nos. 4,022,479, 4,114,902, 4,175,752, 4,706,968 and 4,466,620, all to Orlowski. In such typical labyrinth type seals, internal labyrinth type grooves are provided in a metal seal ring which is fixed to a bearing housing. These grooves are specifically contoured to create an hydraulic dam effect which acts to remove lubricants moving axially along the shaft and pass them back into the bearing housing through a single axially extending drainage groove or trough. Other such seal rings are known in the art.
While the prior art seals of this general type have been effective in their sealing function, a problem common to all of them is that the positioning of the drainage groove or trough is critical to proper seal operation. Thus, when such a seal is installed around a horizontal shaft, the drainage groove or trough must be oriented to be at or very close to the lowest possible position relative to the shaft and the bearings or else the seal will not function properly. In some situations, persons not aware of the importance of proper positioning, could readily install such seals in a non-functional position. Also, even where it is known that the rotary shaft must be in a horizontal position and that the drainage groove must be directly under the shaft, there exist many applications where the final position of the bearing housing or support, and thus that of the drainage groove, may not be known prior to installation of the seal. For example, motors may be installed on the floor, on a wall or even suspended from a ceiling.
Thus, there is a need for a labyrinth bearing seal for rotary shafts which can be installed without regard to its orientation in the bearing housing and yet which will function effectively whatever its rotational orientation with respect to a horizontal rotary shaft to be sealed.